Regenerative synchronous electrical charge extraction for highly coupled piezoelectric generators

This paper proposes a new strategy for vibration harvesting using piezoelectric material. This work relies on an adaptation of the classical Synchronous Electrical Charge Extraction (SECE). Instead of harvesting the energy at every displacement extremum, we choose to wait a certain number of extremum before harvesting the accumulated energy. This technique extends the harvested power compared to SECE, especially with highly coupled piezoelectric generators. It is notably shown that this strategy largely increases the harvested power as the product km
²
Qm gets greater, and at the same time optimizes the switching losses. Measurements on a piezoelectric energy harvester (PEH) exhibiting a relatively large global coupling coefficient have been realized and have proven the efficiency and potential of this technique (193% harvested power improvement at resonance compared with a standard SECE strategy).